What happens when you 'break' a generator?
Frank Millman
frank at chagford.com
Tue Jul 29 03:18:42 EDT 2014
Hi all
Python 3.4.1
Here is a simple generator -
def test():
print('start')
for i in range(5):
yield i
print('done')
x = test()
for j in x:
print(j)
As expected, the output is -
start
0
1
2
3
4
done
Here I break the loop -
x = test()
for j in x:
print(j)
if j == 2:
break
Now the output is -
start
0
1
2
'done' does not appear, so the generator does not actually terminate. What
happens to it?
My guess is that normal scoping rules apply. Using my example, the generator
is referenced by 'x', so when 'x' goes out of scope, the generator is
garbage collected, even though it never completed.
Is this correct?
Frank Millman
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